There are three adjustments in an alignmint: camber, caster, and toe.
Toe is the adustment made at the tie rods. Toe adjusts how parrallel the front tires are to each other. Toe has "NO" effect on the vehicles ability to track straight. Toe is the most important adjustment for tire wear. / \ <--overhead view of tires
Camber is the adjustment of how straight up and down (plumb) the sidewall of the wheel/tire is. Camber has very little to do with the vehicles tracking unless it is way off like a stock car would tilt the tires to the left to fight centrifical force. Eventual tire wear will effect tracking. \ \ <--- looking at the front of the vehicle.
Caster is the angle the ball joints are to each other. Just like a front shopping cart caster wheel, except they tilt the other way. This is the only adjustment that directly effects the vehicle's ability to track straight. If one wheel angles more or less then the other, It will pull. / <---upper ball joint
O <---tire
/ <---lower ball joint
Unfortunately (if my memory serves me right) the only adjustment possible on your two wheel drive truck is toe. 4x4s do have the ability for caster. Top of the line alignment/frame shops have the ability to heat and bent parts to make the adjustments. Also, the natural crown built into almost all roads, for water drainage, will push the vehicle to the right. This is often accounted for at the factory. I have heard of aftermarket adjustible ball joints that may help. A sticking brake caliper, which our vehicles are prone to, will also cause the vehicle to pull. I hope some of this highly interesting information (joke) helps. Sorry for the poor diagrams. It's the best I could do.